To study the fiber components which mediate pain sensations in the peripheral nerves, electrical stimulation and recording of the saphenous, splanchnic, cervical sympathetic and vagal nerve of the cat were carried out under various experimental conditions. Special emphasis was made in reference to the response thresholds, conduction velocities and magnitudes of the various components in the response to change of temperature, dosages of local analgesics and of anti-inflammatory agents. BIBLIOGRAPHIC REFERENCES: Li, C.L., Mathews, G. and Bak, A.: The Action Potential of Somatic and Autonomic Nerves. Exp. Neurol. 56:527-537, 1977. Li, C.L., Mathews, G. and Bak. A.: Effect of Temperature on the Response of Cervical Vagal Nerve. Exp. Neurol. 709-718, 1977.